When you decide to add a suspension lift to your truck, it's important that you be attentive to all of the components of the drive train. Overlooking a component such as the rear drive shaft can be a serious concern, because a drive shaft that is too short will connect at a sharp angle that may cause poor handling. If you are familiar with where to find the drive shaft and transfer case on your truck, you can measure for a new one on your own, making it quick and easy to get a custom shaft that fits properly. Here's a look at the basics of the drive shaft and how to get the measurements.

Understanding the Suspension

Your truck's suspension was designed with a precise geometric connection so that all of the components work well together without binding. When you engage the four-wheel-drive, it locks the transfer case and turns the drive shaft connected to the rear axle. This drive shaft turns the rear axle in conjunction with the front.

When you add a lift kit to your suspension, you alter the ride height, which changes the angles and geometric relationship of all of the suspension parts. Most lift kits include longer or otherwise modified suspension parts to account for this and restore the balance, but the longer rear drive shaft may be optional. The fixed length of your stock drive shaft may leave it connecting at a steep angle, which will cause pressure on the internal shaft components and may damage it.

Getting the Proper Measurements

If you decide that you want to upgrade your drive shaft with your lift kit, you'll have to measure for the new one after the rest of the lift is installed. You'll need that new lift in place first, because that's the only way you'll be able to determine the actual ride height from the new suspension components.

Raise your truck up on a jack and place jack stands on the axle shafts at each wheel. Then, get underneath the truck and find the u-joint on the transfer case that faces the rear axle. Take a measurement from the flat outer section of the transfer case to the flat surface directly across from it on the differential of the axle. The differential is the large round section near the center of the axle.

Then, you'll need a measurement of the distance from one side of the u-joint cap to the other. This is the U-shaped connection where the drive shaft attaches to the axle and the transfer case. You need to be precise about this measurement, because the driveshaft has to fit these joints securely to be safe.

Take the length and u-joint width measurements to a shop that specializes in custom truck parts. They will be able to build a drive shaft that will fit your truck properly with the new suspension.

For more information, contact Pacesetter Truck Caps & Accessories Inc. or a similar company.